Abstract: Background：The clinical manifestations of primary ciliary dyskinesia(PCD) are relatively diverse and often undiagnosed or delayed in diagnosis and treatment. Objective：To investigate the clinical characteristics and genetic spectrum of primary ciliary dyskinesia in children. Design：Case series study. Methods：The medical records system was used to collect clinical information on PCD gene-positive children admitted to Children's Hospital, Zhejiang University School of Medicine between June 1, 2017 and December 31, 2023. This information included gender, age of onset and diagnosis, clinical manifestations, auxiliary examinations, and genetic testing results. A search of Chinese and English databases was conducted to include case series reports of PCD with PCD-related gene positivity in China. The search period spanned from the establishment of the database until December 2023. This study summarises the clinical phenotypes and genotypes of PCD cases in China, as well as their distribution across various regions of the country. Main outcome measures：Clinical characteristics and genetic spectrum of children in China. Results：Thirteen children diagnosed with PCD were analysed, comprising of 7 boys (53.8%) and 6 girls. The median age of onset was 9.0 years (ranging from 3 days to 14.3 years), and the median age of diagnosis was 11.3 years (ranging from 24 days to 14.9 years). The study found that the most common clinical manifestations were cough and expectoration in 11 cases (84.6%), sinusitis in 10 cases (76.9%), fever in 7 cases (53.8%), bronchiectasis, visceral transposition, and atelectasis in 6 cases each (46.2%), nasal congestion, purulent nasal discharge, and Kartagener syndrome in 4 cases each (30.8%). Thirteen children were found to have eight gene mutations. Of the 23 double allelic gene mutation sites identified, 4 cases were related to DNAH11 gene mutation (28.6%), 3 cases to DNAH5 gene mutation (21.4%), and 1 case each to CCDC114, DNAH9, DNAAF3, ODAD1, CCNO, and RSPH1 gene mutations. ACMG classified 8 mutations as pathogenic, 7 as possibly pathogenic, and 8 as variants of uncertain significance (VUS). All 8 VUS sites were predicted to be deleterious by protein function software prediction. This analysis includes seventy-two case series reports or case reports including 391 PCD cases and 316 gene-positive cases. A total of 40 PCD-related genes were detected. The top five most frequent gene mutation sites were DNAH5 (21.2%), DNAH11 (17.7%), CCDC40 (7.9%), HYDIN (6.6%), and CCNO (6.0%). The most frequent clinical phenotypes of PCD cases were chronic cough and expectoration (91.3%), chronic sinusitis (87.0%), bronchiectasis (70.6%), and abnormal lung function (64.2%). In Beijing, Shanghai, and Zhejiang province, the main gene variations were DNAH11 and DNAH5. In Chongqing, the main variation was HYDIN (19.1%), while in Guangdong province, it was DNAH1 (22.2%). In Guangxi Zhuang Autonomous Region, the main variations were RSPH4A (13.3%)、HYDIN (10.0%)、DNAH11 (10.0%)、CCDC40 (10.0%), and ZMYND10 (10.0%). In Hunan province, the main variations were DNAH5 (18.2%) and DNAAF4 (13.6%). Conclusion：In China, the most commonly occurring genes related to PCD are DNAH11 and DNAH5. The main clinical symptoms include respiratory issues, such as persistent coughing, expectoration, and chronic sinusitis.

Key words: Primary ciliary dyskinesia, Children, Gene, China